Two undersea cables in Baltic Sea disrupted

> Can’t they tell the Russian non-combat ships (or pressure them) to get lost?

Not in international waters, which is where submarine cables are largely located.

And even if they could: The oceans are... kind of big. If it were that easy to "just patrol" shipping lanes/submarine cable tracks etc., why would piracy still be a concern?

Would relatively cheap AI-piloted satellite connected ships with sensor equipment work as a solution?

I doubt it. It seems to be a similar problem to missile defense: When you have a lot of ground to cover and can only be in one place at a time, the defender will always be at a huge cost disadvantage compared to the attacker. That's only in one/two dimensions – add a third (submarines) and the cost imbalance shifts even more.

And even if it works, this will only give attackers pause that are deterred by attribution.

Basically if mass produced something makes defense "cheap" it likely makes offense even cheaper.